Most prior art liquid tight connectors for either flexible metallic or non-metallic conduit require the use of a gasket where the connector contacts the conduit to insure water-tightness, especially in those cases where the end of the conduit has not been cut perfectly square prior to attachment to the connector. In such instances, the separate gasket provides a flexible seal against which anomalies in the contacting surfaces of the unevenly cut conduit can be sealed by butting contact.
U.S. Pat. No. 4,457,444 to Snow et al issued Jul. 3, 1984 describes a connector for a liquid tight, flexible electrical conduit formed of a plurality of interlocking, thin, arcuate metal sections having an interior wall of alternating ridges and grooves. The connector includes a ferrule end insertable into the conduit with a plurality of spatially separated arcuate segments matching the conduit grooves for threadable engagement. A resilient seat member, snug fit onto the ferrule end is engaged by the conduit end as the conduit is threaded onto the ferrule to sealingly terminate the full perimeter edge of the conduit end, thereby enabling the conduit and connector assembly to be liquid tight. One or more ramp formed barbs are provided on one or more of the ferrule arcuate segments to lock and secure the connector on the conduit. While this connector is very useful with so-called "armored" metallic conduit, its design does not permit its successful use with flexible non-metallic and a variety of other types of flexible metallic conduits that include, for example, a polymeric waterproofing layer as an integral portion of the flexible conduit. Such conduits are often referred to as Greenfield conduit and include a PVC covering to prevent water intrusion.